One of the main causes of land pollution is deforestation. Forests and their biological wealth are among the most important natural assets of the world. Forests are important for many reasons.
They protect the soil from erosion, which is the habitat of millions of species of plants and animals. They also help to moderate the climate, as they are a major factor in carbon exchange with the atmospheric carbon, and they provide the supply of timber, wood and food. Deforestation is a major problem in Africa.
The rate of the destruction of the African tropical rain forest is particularly very high. It was estimated that between 1930 and 1970 about 25% to 30% of the African tropical rainforests was destroyed.
Another study estimated about 7.3 million hectares of the world’s tropically closed forests were cleared annually between 1976 and1980 with the vast majority (6.1 millions hectares per year) being tropically moist forest.
In Africa, about 3.68 million hectares of tropical forests and woodlands were destroyed annually over this period.
About 1.33 million hectares of tropically closed forests were cleared annually with the vast majority of this area (1.20 million hectares) being tropical moist forest and another 2.34 million hectares of open woodlands in the drier tropics were removed (see Table below).
In the same study, Cote de voire and Nigeria are estimated to be losing 5.2% of their forests annually. With deforestation also carrying the loss of biological diversity. According to one study, 65% of the original wildlife habitat in tropical Africa has been lost.
Read Also : Causes and Effects of Deforestation
Table: Annual Rates of Tropical Deforestation 1976-1980 (Million of hectares per annum)
| Closed Forests | Open Woodlands | ||||||
| tropical of total | All Area % | Moist Area % | tropical of total | % of | Area | Total | |
| Africa | 1.33 | 0.61 | 1.20 | 0.59 | 2.34 | 0.48 | |
| Asia-Pacific | 1.82 | 0.59 | 1.51 | 0.61 | 0.19 | 0.61 | |
| Latin – America | 4.12 | 0.61 | 3.30 | 0.54 | 1.27 | 0.59 | |
| Total | 7.27 0.61 | 6.11 | 0.57 | 3.81 | 0.52 |
The causes of deforestation vary in different countries but four major direct causes are generally recognized for tropical deforestation: conversion of forests for agriculture (both commercial and traditional slash and burn cultivation), wasteful and unsustainable commercial logging, over-harvesting of forest for fuel wood and fodder and conversion of forests to cattle pastureland.
In summary, deforestation has been found not only to contribute to land pollution but also to global warming. The global emission of carbon dioxide of biotic origin due essentially to the deforestation of the tropics in 1980 was estimated at 1,659 millions of tons of carbon a year.